A. Field of the Invention
This invention relates generally to a method and apparatus for monitoring and controlling a remotely controlled receiver to determine the channel to which the remotely controlled receiver is tuned to thereby determine audience preferences.
B. Description of the Prior Art
Various arrangements have been employed to determine audience preferences and viewing habits of television and other audiences. These systems monitor the channel to which a television receiver is tuned, whether the receiver is on or off, and in some instances, whether the receiver is receiving a broadcast program, a cable or satellite program or a program played back from a VCR. A disadvantage of many known monitoring arrangements is that an internal connection to the television receiver is required. For example, U.S. Pat. No. 3,973,206 issued to Haselwood et al, on Aug. 3, 1976 discloses a method of determining channel tuning by monitoring the varactor diode tuning voltage and thus, requires internal connections in the television receiver.
Another method for determining channel tuning disclosed in U.S. Pat. No. 4,425,578 issued to Haselwood et al on Jan. 10, 1984 utilizes a signal injection source and a detector/receiver arranged to detect the combined signal from the injection signal source and a video carrier to which the video receiver is tuned. A significant drawback of signal injection monitoring arrangements is the potential interference with the functional operation of the video receiver being monitored.
U.S. Pat. No. 4,723,302 to Fulmer et al, issued Feb. 2, 1988 and assigned to the same assignee as the present application, discloses another method for determining channel tuning utilizing a local oscillator frequency measurement of the monitored receiver. The disclosed method and apparatus while effective for its intended purpose generally requires that a probe be positioned at a selected location in the monitored receiver and thus requires physical access to the receiver.
U.S. Pat. No. 4,697,209 to Kiewit et al, issued Sept. 29, 1987 and assigned to the same assignee as the present invention, discloses another method and apparatus for determining channel tuning. This method involves intrusively monitoring the ON/OFF states of a television receiver and a VCR, extracting a signature from a video signal, and comparing the signature comparing with a reference signature to determine the tuned channel.
Access to the tuning mechanism is becoming increasingly difficult with the advent of cable and pay television systems that utilize various converters and decoders, many of which are difficult to access. U.S. Pat. No. 4,876,736 also to Kiewit filed on Sept. 23, 1987 and assigned to the same assignee as the present invention, discloses a method and apparatus for monitoring the status of a remotely controlled television tuner by interposing a translating and logging device between the television tuner and a special remote controller supplied to the user. The translating and logging device receives the signals from the special controller, logs them, translates them from the format used by the special controller into a format acceptable by the television tuner, and retransmits the translated signals to the television tuner. This system allows channel monitoring without physical access to the receiver but has the disadvantage that the user must give up the user's own remote controller in favor of the special controller, which may or may not have the special features which the user desires.